One of the major findings of Robert Putnam and David Campbell's important 2011 study American Grace: How Religion Divides and Unites Us is the rise of what scholars of religion call "the nones": a rising tide of religiously unaffiliated Americans, which is now in the neighborhood of 20% of the U.S. population. (See my review here.) Such a statistic is often cited as an example of how, amid the prominence and evident power of evangelical Christians in U.S. society (who, by the way, tend to see themselves as beleaguered), the nation is becoming increasingly secular. But in Families and Faith, sociologist Vern Bengtson and collaborators Norella Putney and Susan Harris report that the picture is somewhat more complicated. To be sure, they say, there has been significant churn in religious identity since 1970. But there's also been a lot more continuity than you might think.

Families and Faith is a brief distillation of The Longitudinal Study of Generations (LSOG), a 35-year project begun by Bengtson in 1970 drawing on over 2,000 respondents in over 350 multi-generational families. The goal of the study was to analyze patterns of religious transmission, or lack thereof, across four generations. In the broadest sense, what Bengtson found is that about six in ten children kept to the religious tradition of their parents -- more for Mormons and Jews, less for Catholics and mainline Protestants.

You can interpret that as a glass that's a little more than half full or almost half-empty, depending on your predilections. But Bergston leans toward the former, for a number of reasons. One is that many of those who have not maintained faith traditions in any formal sense nevertheless profess loyalty to them and eventually return to them (the so-called prodigals). Another is that non-religious affiliation is itself significantly a matter of generational transmission. Contrary to a widespread perception that unaffiliated Americans (only a small percentage of whom are avowed atheists) typically drift away from or rebel against family traditions, about two-thirds of such people very are very often affirming active or implicit family non-practice. Perhaps most fundamentally, while the rate of transmission may not seem all that impressive, it's essentially unchanged since 1970 -- which is to say that the tremendous social transformations that have occurred since that time (e.g. race, gender, sexuality) have had little impact on the underlying rhythms of religious continuity.

An early chapter of Family and Faith discerns a distinctly generational flavor in patterns of religious conception and intensity -- Americans born in early decades of the twentieth century, for example, tend to consider religiosity and spirituality as essentially interchangeable, while those born later in the century increasingly distinguish between the two (and place greater emphasis on personal spirituality than collective religiosity). But in general, the study shows that the single most important influence on outcomes for children is the tenor of parental commitment. In general, if you want to have religious kids, you should marry someone in the same faith, actively practice that faith in a religious community, and demonstrate that faith in your everyday life. That's not surprising. Nor is it surprising that life events like divorce or family stress weaken religious ties. Or that remote or hypocritical parenting has obvious implications for whether or not children keep the faith.

But here's something that is surprising: It's fathers more than mothers who tip the balance (except among Jews for whom inheritance is matrilineal). A remote or authoritarian father is one of the surest ways to snuff out religious feeling among children. Here's something else: grandparents play a major and growing role in shaping outcomes. Though if you think about it for a moment it's easy to see why -- not only are they living longer, but they in many cases are doing a significant amount of child-rearing.

If there's one thing that's clear in Families and Faith, however, it's that there's no sure-fire formula for having your children follow your preferred path. Except, perhaps this: exhibiting an element of tolerance toward your kids, of making clear that the decision to choose the faith of their fathers is just that: a choice. Whether or not that's a typically American approach to God, it seems to be the one works best on these shores.